Doppler radars cannot work on a satellite as the beam should be almost parallel to the earth's surface. They are used to remotely measure the wind speed and are useful in detecting rotating winds, thus tornadoes.

... on my local cable system, The Weather Channel has been replaced by the lamer WeatherNation...

There's something lamer than the Weather Channel? Hard to imagine. It was ok (exception noted below) before they tried to be the next Today show, now it's approaching worthless. I don't want endless moronic, idle chitchat, I want the weather.

Exception: whoever thought it was a good idea for the Wx Channel to broadcast all the idiotic reality crap needs to go back to the janitorial crew.

13. The Commission’s investigations found that most 5 GHz devices are manufactured to enable operation across a wide range of frequencies, extending down into the 4 GHz bands and up to almost 6 GHz. The devices are controlled by software that manages the specific parameters used in theequipment. In most of those cases for which a specific cause was determined, the harmful interference was the result of third parties or users modifyin

It would also require notching out the TDWR frequencies, instead of allowing them to be used with DFS. I suppose someone could create a fuse controlled radio chip which could be used worldwide, and fuses blown during manufacturing to limit the hardware as required, but somehow I don't think the market is big enough for that to happen anytime soon.

Actually, if you read the document, there was a pretty substantial pissing match between Globalstar (providers of satellite cell service) and the device manufacturers, over technical details having to do with harmful interference to Globalstar's uplink and downlink.

The whole thing started when it was noted that there were devices in the field interfering with doppler weather radar, and that those devices could transmit outside their assigned frequencies by altering parameters through software.

Um, no. Amateur radio people were also having trouble with this, too. If you needed a good reason, however, interference with radar is a really good reason to limit use of this part of the unlicensed spectrum. Freebies are one thing, but we have to play together or we'll start jamming each other.

In particular, we noted that enhanced spectrum use may be possible when devices use a very high bandwidth and the number of usable channels is small. We also noted that the trend for U-NII devices is to operate with ever wider bandwidths such as contained in the new 802.11ac standard.

By reducing channels the spectrum can better accommodate high speed protocols like 802.11ac, which can achieve 500 Mbps in single link systems.

The same thing happened in 2.4GHz 802.11. The radios that prevail today emit over many of the legacy channel numbers to achieve contemporary throughput with "N" systems. There are only 4 non-overlapping channels used in N; 1, 6, 11 and 14. That's why most N radios won't let you pick "3" for insta

> the Commission’s Enforcement Bureau found that certain models of devices certified for use in these bands were designed in a way that users were ableto disable the DFS mechanism. With the DFS mechanism inactive, the device could transmit on an activeradar channel and cause harmful interference.

and:

> Early field studies performed by the National Telecommunications and Information Administration’s (NTIA’s) Institute for Telecommunications Sciences (ITS) and FAA staff indicated the interference sources were certain unlicensed U-NII devices that operated in the same frequency band as these Federal radar systems. This interference was occurring despite the Commission’s rules that require U-NII devices operating in this band to incorporate an interference mitigation technique called dynamic frequency selection (DFS).

Oh look, people buying illegal 1Watt emitters from China and attaching them to bigass antennae to "deliver internet in rural areas" on fixed channels without DFS when regulations strictly say "nope", now crying that they're being "stepped on".

Or just old 802.11a devices that pre-date the Dynamic Frequency Selection requirements.

I think DFS was mandatory for 802.11a in order for it to even use the band - otherwise no one would approve the use of it. There's even a bit in the management frame to be used when radar is detected and for everyone to switch channels.

All the FCC did was find it was possible on some devices to disable it to force it to use a specific frequency.

Except that population density isn't an important factor. It is how they are distributed. A high or low population density doesn't tell you whether the population is strung out in rural areas or if they are all in one mega city in the middle of the state. A 200 sq. mile area with four cities each having 5k people and the same area with a single city containing 20k people have the same population density but who do you think is going to get better access?

Finland's average speed to the sites in Finland may be awesome. Average speed to the sites I want to visit?

Just because the last mile is fast doesn't mean that its useful.

Stop cherry picking metrics to go off ranting about. There comes a point when faster isn't really needed for your usage. I can get 50mb, but why bother, 99.99% of the time it would be wasted and do nothing but cost me more.

Of course, I'm also in a city thats on the list for Google Fiber soon so I'll probably be changing my story after g

Finland's average speed to the sites in Finland may be awesome. Average speed to the sites I want to visit?

Just because the last mile is fast doesn't mean that its useful.

Really? I have yet to see a faster last mile that hasn't resulted in a faster overall experience. The sites I want to visit? Most of them host content on the likes of Akamiai.But don't feel bad people have been saying this for years. They said it about the 56k modems, they said it about the first ADSL modems, they said it about cable, and they are saying it now.

I guess you don't realise that in the last 15 years the service providers pipe's have grown just as fast as the last mile.

Just because it has a similar population density does not make it a valid comparison. Look at the two maps below, Nearly a quarter of their 5.4 million people live in Helsinki alone. If all of them have 100mbs connections or better it will be easy to have an average speed 5x the USA even if those in rural areas have no internet connection at all. I know it is popular to hate on the US for doing a crappy job rolling out broadband but we really have to stop comparisons to countries that are distinctly differe

How do you justify running a fiber service out to those areas? The population density in most rural areas just does not justify the expense of installation, to say nothing of cost of upkeep compared to the income from your customer base. Wireless is really the only financially responsible means of covering these low population areas.

Oddly enough, there is fiber already installed in some remarkably rural areas. none of it being used, but it's there.

Even then, all the "wireless" or Broadband over Power line" solutions are really last mile solutions. You are going to need fibre in the equation. note: Satellite is one exception, though slow.

The reasons for attempting to go wireless are more ideological than technical. A modern day version of the "Rural Electrification Act" is too socialistical for us now. So we'll just do without. http [wikipedia.org]

Bullshit. I work for a telco that is doing exactly that in an extremely rural population, and other rural telcos in our region are already 100% done with their deployments. To all their customers! Wireless is a joke for professional WAN use (ISP, telco, cellular backhaul, etc.) no matter what the US cellular industry says. Upkeep is minimal compared to antenna systems and power requirements for those installations.
Curious why you posted your crap AC, if you truly belive what you say and aren't just a

They're trying to protect Terminal Doppler Weather Radar, they've added restrictions on the upper band but removed the indoor restrictions on the lower (5.2ghz) band. A fair tradeoff in the opinion of someone that used to work at a WISP.

Is the Doppler Weather signal not modulated so that error correction can be performed? This safety system is vulnerable to simple unintentional analog interference? Can somebody please send over an RF engineer?

Is the Doppler Weather signal not modulated so that error correction can be performed?

If your receiver is swamped by what looks like broadband noise, what signal do you have to 'error correct'? And when you're talking about Doppler radar, you are essentially transmitting a pure signal and looking for the "errors" in the bounce-back. Doppler radar is not a stream of digital information that can have FEC or ARC attached to deal with dropouts and noise. There is neither checksum nor NACK to force a retransmission.

This safety system is vulnerable to simple unintentional analog interference?

Not necessarily that it's a "safety system", but vulnerable, yes. As are the OTH

Is the Doppler Weather signal not modulated so that error correction can be performed? This safety system is vulnerable to simple unintentional analog interference? Can somebody please send over an RF engineer?

The whole system works on weak return signals, and someone broadcasting a strong jamming signal will just swamp the intelligent signal.
But not to worry, anyone jamming will stick out like a sore thumb, leading the F.C.C. right to their antenna.

Rain and snow definitely cause a fade in signal strength but if you've properly engineered the link you'll stay within acceptable signal levels. The WISP I worked for in Minnesota had to deal with plenty of rain and snow..

Anyone setting up commercial wireless links should know that they have to engineer for worst possible scenarios.

I was thinking exactly the same thing. 2.4GHz has trouble getting through multiple walls. Television is much lower frequency (800MHz-ish I think) and it can't handle buildings or hills. FM radio can't handle large solid areas either (and I think that's 90-100MHz). They think 5GHz is going to get internet out to rural areas? It wouldn't even get it out to my patio from my office. Rural people had at least 10 years to move back to civilization so if they want internet so if they're still acting like it'

You and the other replier apparently aren't aware that cities with 50,000 people exist. To drive from our inner city urban area to our suburbs takes 15 seconds, sometimes 30 if you hit a light. A 2000 sq ft house costs about $150,000 brand new and in an ideal zone. To drive out to a wooded area or farming area takes about 6 minutes from the center of the city. A street hot dog costs about $2.50-$4. The standard $38/mo internet connection is 15 megabits and you actually get 15 on a test (unless you're w

I'm aware that cities of 50,000 exist. You're apparently unaware that farmers need Internet access in the modern age, too. Specialized weather data that a lot of them rely on has moved online-only for just one example.

Complain about no Internet for good reason? Phone companies are already ripping out copper anywhere that's not super profitable. The Universal Service Fund was created to guarantee them telecommunications access. It seems that Internet access isn't considered to be telecommunications by t

You're apparently unaware that farmers need Internet access in the modern age, too.

You are apparently unaware of the meaning of the word need.

No one needs the Internet. Using the wrong words utterly destroys any point you might be trying to make by showing how you don't actually know what you're saying or are just being ridiculous in your statements.

Back in the day before the digital conversion, when analog TV channels were actually on the channel number by which they called themselves, Channel 2 started at 54MHz, and Channel 83 had an upper edge of 890MHz.

A channel 2 signal would wrap around a pine tree in the line of sight from transmitter to receiving antenna and keep going, but said tree would stop Channel 83 stone cold dead.

(It's kind of like how you can run both channels into a single sub-woofer because those frequencies are so non-directional,

As far as I'm concerned "microwave" is 2.4 gig. (And maybe lower, but your microwave oven operates around 2.4 gig.) 5 Gig is over twice that. How do you justify the word almost? Where do you think microwave starts???

Microwave does not mean microwave oven. Microwave is at the very least a range from about 1GHz to 300GHz.
And this is where you reply and tell me I missed the joke.

No joke, just that you've fallen for the old "all A is B means all B is A" logical fallacy. He said that microwave ovens use 2.4GHz and thus microwaves must be at least as low as 2.4GHz, not that the only microwave frequency is the frequency used by microwave ovens. I.e., "microwave means microwave ovens" is your backwards interpretation of what he said, which was, in essence, "microwave ovens means microwaves" are used.

You also missed the context, which was that the OP said that 5.8GHz was "almost microw

I interpreted it as him saying 5GHz is double what a microwave puts out - not almost, but way beyond microwaves. Missing that it goes way beyond 2.4GHz. And he also said "maybe lower" than 2.4GHz, which kind implied to me "maybe lower, but definitely not higher"

Your reading of it makes more sense, but you certainly didn't know what I was saying because you read his post differently.

video streaming is not a higher-bandwidth application. It's 10Mbit/s. It's not broken all over the place for lack of edge or indoor bandwidth, you idiots. It's broken by packet loss and unreliable channels indoors, poor buffer management at the edge, and massive strategic oversubscription at the city level by the eyeball monopolies.

This spectrum was introduced in 1997 to augment the "last mile" cost for rural subscribers, particularly schools and libraries. It doesnt come with license fees and as such is widely used by private industry to provide internet access to paying customers who live in the middle of nowhere (many of whom dont even have cellular service.) the existing bandwidth peaks at a blistering 25mbit.

as an amateur radio enthusiast, U-NII band reform is a long time coming and private companies have a huge incentive to get you to oppose it. thittesd0375 doesnt say it, but these arent petitions you're filing either, they are official FCC proceedings and considered a complaint, which is very different than the change.org crap that shows up on slashdot one a month. holding on to this band plan and its users is an easy way for telecom companies to quietly interfere with projects that would actually help citizens like wimax and municipal gigabit/wireless. If you have any respect or concern for the people being screwed over for 25 megabit service initially intended for public education around the same time AOL was all the rage, you should probably avoid this slashdot article entirely.

Actually, current equipment is capable of delivering 150mb+ per 40MHz sector and new AC based equipment, that was just announced today, is capable of 450mb+. This has huge potential for bringing service to these underserved areas.
http://www.ubnt.com/airmax/roc... [ubnt.com]

Most of my 2.4 GHz links have been removed from service since the band is so crowded, that even with -50dBm signals the throughput was crap, but one is almost by themselves on 5.8 GHz (almost no 802.11a, a few TDMA stations, mostly AirMAX, around), and can get great throughput and reliability with weaker signals...If I were starting a WISP now, I would do only 5.8 GHz and 24 GHz links.

My father in law is in a rural community. He has hundreds of acres of land and he has to use a wireless provider for internet. But he's also got dark fiber running up to his mailbox. After the cable was laid all over the county, nothing was done with it. How about taking the opportunity to push ISPs to light up that dark fiber for rural areas. If you have telephone service you should also have broadband capability.

Citizen! When Comcast is ready, they will terminate that fiber with high quality coaxial cable and make available to you a quality entertainment bundle with hundreds of television channels and the opportunity to purchase many more. You will also gain a generous, metered Internet connection at only a small additional expense and Comcast will do its best to make sure you have just enough bandwidth to watch your Netflix in 240P with only a minimum of buffering.

No one gives a shit about your crappy little 5.8ghz FPV system. Your toy is not a serious problem.

People who fly anything more than a pre made toy don't use 5.8ghz, it sucks ass for range. 2.4ghz is only marginally better, and anyone who actually cares uses 900mhz.

As was stated if you'd bothered to read, the bandwidth in question is also right around the area used by most doppler radar stations, which means random broadcasts from unregulated devices screw with doppler radar.

People who fly anything more than a pre made toy don't use 5.8ghz, it sucks ass for range. 2.4ghz is only marginally better, and anyone who actually cares uses 900mhz.

As was stated if you'd bothered to read, the bandwidth in question is also right around the area used by most doppler radar stations, which means random broadcasts from unregulated devices screw with doppler radar.

For sure. Remember though, we are dealing with digital people. While they know their digital, they make a few glaring errors when dealing with RF.

Going to go into a related rant now.......

One of them is the weird idea that somehow, some way, bandwidth is infinite. It isn't. One of the best charts I've ever seen to illustrate this is here:

Most FPV transmitters are at 5.8Ghz. Used to be important that you were hitting this as close to 5800Mhz as possible so as to stay in the middle of the ISM band. Really hard to believe these 500mw transmitters can cause a signature on Doppler when most times they drop useable signal after 1200 meters.

It does seem that the FCC and the FAA are working together on this. The FAA specifically targeting FPV last week, and now the FCC trying to take back the same radio band this week.